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Projectile Motion
Problems
SEPTEMBER 26 AND SEPTEMBER 29, 2014
Projectile Motion Problem
Solving Steps
To solve projectile motion problems, you must separate the
horizontal and vertical components of motion.
1)
Resolve the launch velocity to find the vix and viy. (Use SOH
CAH TOA)
2)
Divide your paper into two sections – one for horizontal and
one for vertical
3)
Write the relevant equations and known variables in the
appropriate sections
4)
Recognize that horizontal and vertical sides are linked by time
in the air. You may use time to find other variables on either
section.
Problem 1: Soccer kick
A player kicks a soccer ball from ground level with an initial velocity of 27.0
m/s, 30o above the horizontal. Find each of the following. Assume that air
resistance is negligible.
a)
The ball’s hang time
b)
The ball’s maximum height
c)
The horizontal distance the ball travels before hitting the ground.
Problem 2: Giraffe assembly line
Lucy and her friend are working at an assembly plant making wooden toy
giraffes. At the end of the line, the giraffes go horizontally off the edge of
a conveyor belt and fall into a box below. If the box is 0.60 m below the
level of the conveyor belt and 0.40 m away from it, what must be the
horizontal velocity of giraffes as they leave the conveyor belt?
Problem 3: Rock thrown from cliff
A rock is thrown from a 50.0 m high cliff with an initial velocity of 7.0 m/s at
an angle of 53o above the horizontal. Finds its velocity when it hits the
ground.
Problem 4: Rock thrown from cliff 2
You throw a stone horizontally at a speed of 5.0 m/s from the top of a cliff
that is 78.4 m high.
a)
How long does it take the stone to reach the bottom of the cliff? 4.0 sec
b)
How far from the base of the cliff does the stone hit the ground?
c)
What are the horizontal and vertical components of the stone’s
velocity as it hits the ground?
You Do
20 m
Vx = 5.0 m/s
Vy = -39.2 m/s
Problem 5: Darts
A dart player throws a dart horizontally at 12.4 m/s. The dart hits the board
0.32 m below the height from which it was thrown. How far away is the
player from the board?
3.2 m
You Do